Train-carried receiver for automatic train-control systems



C. H. ZIERDT' May 10,1927.

TRAIN CARRIED'RECEIVER FOR AUTOMATIC TRAIN CONTROL SYSTEMS Filed March 19. 1926 INVENTORZ d. P/ W M4 ATTORNEY Patented May 10, 1927.

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CONE-AD HJZIERIDT, OF ROSEDALE,-PENN TOWNSHIP, ALLEGHENY COUNTY, PENNSYL- VANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE,

PENNSYLVANIA, A GORPORATION"OF SYLVANIA. Y

TRAIN-CARRIED REGEIV'IEJRF013 AUTOMATIC TRAIN-CONTROL SYSTEMS.

.Appilicati-onzfiled March 19,.1-926. Serial-"N 295,863.

aMy invention relates 'to automatic train control systems of the-type whereintra n carried apparatus "1S controlled at least 1n part-by an alternatingcurrent which flows through the two track rails in multiple. More; specifically, my present invention relates to .atrain carried receiver for use [i111 systems of this character.

One object of my invention is thc provision of a receivcr which will supply energy to the train carried apparatus in accordance with the train controlling current in the track rails, but which willnot supply energy tozsuchuapparatus in accordance with alternatiing currentsflowing in ,adjacenttransmission .lines or in .:a(djacent tracks, etc.

I will describe one form of receiver embodyingmy invention, and Will'fll-Gll point out the novel features thereof in claims.

"In the accompanying drawing, Fig. 1 is a diagrammatic view showing a portion of an I automatic train control system including one form of receiver embodying my invention. Fig. 2 is a front View of the receiver A shown in Fig. 1.

Similar reference characters refer to si1ni-. lar parts in each of the views.

Referring first to Fig. 1, the reference characters 1 and 1* designate the track rails of a railway, which rails are divided by in sulated joints 2 to form a track section. Connected across the rails of this section at spaced points are two resistances 8 and 3. and connected with the middle points of these two resistances respectively are the two terminals of the secondary 4 of atransformer T. The primary 5 of this transformer is supplied with alternating train controlling current from a suitable source not shown in the drawing. It is understood that in practice the supply of current to the track rails by transformer T will usually be controlled in accordance with traffic conditions, but inasmuch as the controlling means forms no part of the present invention it is omitted from the drawing. It will be apparent that the current supplied by transformer T flows through the two track rails 1 and 1 in multiple, that is, at any given instant it flows in the same direction in these rails.

The reference character W designates a railway train provided with a receiver A embodying my invention. Referring to Fig. 2, this receiver comprises two magnetizable cores 20 and 21. Core 20 isprovided with two downwardly progectmg legs 9 and 10 located OllnOPlDOSltGSlClQS of-the trackrail 1', and core 21 is'provicled with two similar downwardly projecting legs 11 and 12 located on opposite sidesof the'tra-ck rail 1. These legs carry a winding which is made up of iforur coils 13, 14, and 16 lo rated upon theqfour legs 9, 10, 11 and-12, re-

spectively. This winding isincluded in a pickup circuit lithe four coils being connected in series in this circnit in such menthis circuit'is tuned .to resonance at the fre" quency of the current furnishedby transformer '1.

The pick-up circuit B may be used in connection wit-h train carried governing apparatus of any suitable type. As here shown, this circuit supplies energy to one winding 22 of an induction motor relay R, the other,

winding 23 of which is supplied with energy by any suitable means having nothing to do with the present invention. An amplifier is preferably interposed between the receiving circuit B and the winding 1. As here shown, the amplifier is connected across the terminals of the'condenser 7.

The magnetic fluxes surrounding rails l and 1 due to the current from transformer T in these rails, may be represented by the broken lines 17 and 17 in Fig. 2. The flux 17 surrounding rail 1 will pass through coils 15 and 16 in such directions as to create electromotive forces in the circuit B which are additive. Similarly, the flux 17 surrounding rail 1' will flow through coils 13 and 14 in such directions as to create electromotive forces in the circuit B which are additive. Furthermore, the electromotive forces thus created in coils 15 and 16 by the one flux and in coils 13 and 14 by the other flux are additive. An elect-romotive force is therefore created across the terminals of condenser 7 due to current supplied to th track rails by the transformer T.

Foreign magnetic flux from sources adjacent the trackway will pass through the two cores 20 and 21 in the same direction and the electromotive forces induced in the several coils by such foreign flux will oppose each other so that these electrolnotive rorces have no eifect upon the pick-up circuit. For example, fore1gn flux passing vertically through core 20 will induce in coils l3 and 1: electroinotive forces which oppose each other. Similarly, foreign flux passing vertically through core 21 will induce in coils l5 and 16 electromotive forces which are in opposition. properly proportion inn the legs of the cores and the number of turns in the coils, the electrolnotive forces induced in the coils by foreign flux can be made substantially equal and opposite.

It follows from the foregoing that any foreign magnetic flux due to alternating current in a transmission line or an adjacent track, will create little or no electro-inotive force in the pick-up circuit B and will have little or no tendency to cause false operation of the train governing relay R.

Although I have herein shown and described only one form of receiver embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

aving thus described my invention, what I claim is:

1.. A train carried receiver comprising a pair of cores disposed transversely over the two track rails respectively and each provided with two legs projecting; downwardly on opposite sides of the associated rail, and a winding made up of a coil on each leg said coils being connected in series in such manner that the electromotive forces induced in such winding by fluxes due to current flowing in the same direction in the track rails are additive but that the resultant electromotive force created in said winding by foreign fluxes passing through said cores is substantially zero.

A train carried receiver comprising a pair of cores disposed transversely over the two track rails respectively and each provided with two legsprojecting downwardly on opposite sides of the associated rail and a winding made up of a coil on each leg, said CONRAD H. ZIERDT. 

